How is this possible? The reason spinning a bucket of water upside down keeps the water inside the bucket is because you're applying force and accelerating the bucket. But in space, there is nothing 'accelerating' the rotation of a spacecraft, it is merely in continuous Newtonian motion, and the spacecraft and all of its contents would be at rest relative to each other wouldn't they? I thought everything was relative, and what appears to be 'rotation' in space depends on your own frame of reference. So how would could this 'artificial gravity' occur?